Miniature co-axial switch



Feb. 23, 1960 D, H, LANCTOT -2,926,318

MINIATURE CO-AXIAL SWITCH Filed June 26, 1956 IN1/Emol; Donno u. LANcmr 7a FIGA BY imam 2,926,318 MINIATURE CO-AXIAL SWITCH Application June 26, 1956, Serial No. 593,875 3 Claims. (Cl. S33-97) This invention relates generally to broadband radio frequency switches and more particularly, to a miniature co-axial switch for passing R.F. energy from an input co-axial connector to one or more output co-axial connectors.

High frequency co-axial switches are well known in the art and have been developed to a high degree of reliability. In all such switches, the physical layout and design of the switch components themselves are extremely important inasmuch as the wave lengths of the R.F. energy involved are often of the order of magnitude of the physical dimensions of the components. It is extremely important, therefore, that the switches be physically designed toy insure both a good impedance match between the various connectors and maximum isolation between an unused connector and an adjacent operating connector.

Several of the better known types of co-axial switches rely on a rotating switch arm which is arranged to make individual contact with the center conductor of a plurality of co-axial output connectors. An energy -input connector forms a part of the switch arm so that by rotating the arm, the input may be connected to any one of the outputs. While a fairly good impedance match may be achieved with switches of-this type, it is usually necessary to provide a relatively large amount of power to operate the switch. For example, the rotating arm usually makes contact with the various output connectors in a xed pattern so that it may be'necessary to move over several connectors before it can make contact with a desired output connector. In other words, there is no means for directly connecting the input to a desired output without lirst passing through the other sections. Therefore, different physical movements are necessary depending `upon the particular output connector to which a connection is to be made. In the event of electrically operated coaxial switches of this type, a relatively cornplicated index stepping system must be employed to insure that a desired co-axial output connector is placed in operation. The bulk and size of such switches also often pose a cooling problem.

In many present day switches, the physical design is such that all of the various co-axial connectors are not conveniently disposed for making rapid connections to auxiliary apparatus. The input co-axial connector may be facing in a direction different from the output co-axial connectors making it diicult to mount the switch on a convenient working panel. Further, in the case of electrically operated co-axial switches, failure of the electrical actuating means, may leave the input connected to at least one of the output connectors; that is, there is no fail safe provision.

Bearing the above in mind, it is a primary object of the present invention to provide a vastly improved coaxial switch which is small and compact and in which very little power is necessary for operating the switch.

More particularly, an object of the invention is to provide a miniature co-axial switch of the above type in nited States Patent G l 2,926,318 Patented Feb. 23, 1960 ICC which physical movement for effecting the switching between an input co-axialtconnector and any one of several output coaxial connectors is individual to each output connector and extremely small, whereby it is not necessary to pass through other sections before a desired connection is made and very rapid operation is achieved.

Still another important object is to provide a co-axial switch in which the switching components are of relatively short electrical length and suitably dimensioned to insure an excellent impedance match between the input co-axial connector and the various output co-axial connectors.

Another object is to provide a miniature co-axial switch in which those output co-axial connectors not in use are grounded out whereby cross-talk is minimized and a high degree of isolation is attained.

Still another object is to provide an electrically operated miniature co-axial switch which will fail-safe should the actuating electrical power fail.

Another object is to provide a switch of the above type in which all co-axial connectors face forward for convenience in making connections thereto.

Still another object is to provide a miniature co-axial switch which is completely sealed against dirt and dust and which has an extremely long life whereby it may also serve as an antenna lobing switch.

These and many other objects and advantages of the present invention are attained by providing a sealed casing having a flat front connector plate. An input coaxial connector for passing R.F. energy to various coaxial output connectors is centrally located on the plate and the various output co-axial connectors are radially and symmetrically spaced about the center of the plate facing in the same direction as the input connector. VThe plate itself includes a plurality of internal radial passages passing from the central co-axial connector to each of the radially spaced output co-axial connectors. These radial passages have inside diameters corresponding to the inner dimensions of the co-axial connectors whereby a proper impedance match is maintained between the input co-axial connector and the various output co-axial connectors.

The inner conductor of each of the various output coaxial connectors is in the form of a resilient conductor or reed passing centrally down each of the radial passages to a position adjacent to but out of contact with the center conductor of the input central co-axial connector. Each of these reeds are arranged to be independently operated by a suitable electro-magnet and insulated push rod so that any one or more may be placed in contact with the central conductor. The reeds are normally biased to their out of contact position such that when the electro-magnets are de-energized, no connections are made between the connectors. Preferably, each of the push rods for actuating the reeds are arranged to slide in metallic bearing sleeves electrically grounded to the front plate so that when an electro-magnet is tie-energized and the corresponding reed springs back to its out of contact position it simultaneously contacts the metallic sleeve to ground itself to the front plate. Tous, all of the various output co-axial connectors that are in disconnect position have their center conductors grounded ont whereby excellent isolation is obtained between the connected output co-axial connector and the remaining output connectors.

By providing an individual electro-magnet for actuating the reed associated with each output co-axiai connector, each connector may be individually connected to the center conductor of the central co-axial input con nector and thus it is not necessary to switch through various sections before a desired connection is effected.

Further, the relative movement for making or breaking aconnection is extremely small so that a ing operation is possible.

A better understanding of these and other features and advantages of the present invention will be had by referring to a preferred embodiment as illustrated in the accompanying drawings, in which:

Figure l is a perspective view showing the miniature co-axial switch of the present invention;

Figure 2 is a cross section taken in the direction of the arrows 2 2 of Figure l;

Figure 3 is a cross section similar to Figure 2, illustrating the relative positions of the components upon de-energizaton of one of the actuatng electro-magnets;

. and,

in any number which may be easily accommodated by the front plate 12.

Referring now to Figure 2, each of the output co-axial connectors, such as the co-axial connectorslS and 17, are arranged to be respectively placed in electrical connection withV the central input co-axial connector 13 by an electrical actuating means. This electrical system includes an electro-magnet coil 18 for the co-axial connector 15, and a similar electro-magnet coil 26 for the C0- axial connector 17. Two other similar electro-magnetic coils and co-operating components therefor. are associatedwith theoutput co-axial connectors 15 and 16 of Figure l, but inasmuch as they are identical to the coils 18 and 26 description of these two will suffice for a proper understanding or" the invention.

As shown in Figure 2, the electro-magnetic coil 18 is provided with a conventional armature 19 pivotcd at 20 and arranged to engage one end of an insulated push rod 21 slidable within a metallic sleeve 22. The'other end of the push rod 21 is in engagement with a conducting resilient reed Contact 23 shown in its actuated or very rapid switchatacante` 4 by identical reference numerals but the coil 18 is shown de-energized whereby the resilient reed 23 is out of contact with the center conductor contact 25 of the input co-axial connector 13. The reeds 23 and 31 are normally biased to assume the position shown by the reed 23 in Figure 3 such that a positive force is necessary to urge the reed 23 into contact with the central conductor contact 25. As shown in Figure 3, when the coil 18 is deenergized, the armature 19 is free to pivot about the pivot point 2i) to its open position and the armature will be moved to this position by the biasing force of the reed transmitted through push rod 21. The arrangement is such that the reed 23 makes electrical contact with the metallic sleeve 22 upon de-energization of the electromagnetic coil 1S, whereby the center conductor 24 of the coaxial output Vconnector 15 is grounded through the reed against the end of the sleeve 22.

With the components in the positions shownuin Figure 3, it will be noted that the input co-axial connector 13Vis in electrical connection with the output co-axial connector 17. If the coil 26 is now de-energized and the coil 1S energized, the central co-axial input connector 13 will then be disconnected from the connector 17 and connected to the connector 15. It will be noted that the physical arrangement is such that the connection. between the output co-axial connector 15 and input co-axial connector 13 may be elected before the contact between the output co-axial connector 17 and input co-axial connector 13 is broken. In other words, the contact may be made before broken whereby any arcing or interference noises created by the switching operation are minimized.

connected position in Figure 2. This reed forms an extension of the center conductor 24 of the output coaxial connector 15 passing down a radial passage in the front plate 12 towards the central connector 13. As shown in Figure 2, the push rod 21 is in its actuated or energized position holding the end of the reed contact 23 in engagement with a contact 25 connected to the center conductor of the input co-axial connector 13.

Similarly, the electro-magnetic coil 26 is provided with an armature Z7 pivoted at 2S for actuating a push rod 29 sliding within aY metallic sleeve 3@ for engaging a similar conducting resilient reed contact 31 connected to the center conductor 32 of the output co-axial connector 17. 1n Figure 2, both the resilient reeds 23 and 31 are shown in their operated position, that is, in Contact with the' central'conductor contact 25 whereby a T connection is provided in which l-F. energy entering the input co-axial connector 13 is passed to both the outer co-axial connectors and 17. r1`he reed 23 and internalradial passage through which the reed passes are dimensioned similarly to the physical dimensions of the co-axial connector such that a proper impedance match is provided between the co-axial connector 15 and the central co-axial connector 13. The reed 31 and its associated radial passage Vare also similarly dimensioned. The electro-magnetic coils 18 and 25 are energized by applying electric current between the respective terminals 34 and 35 at the rear of the casingV 10 and ground.

ln Figure 3, the same components have been identified.

Referring to Figure 4, the physical arrangement of all four of the various output co-axial connectors and the manner in which they may be individually connected to the center conductor Contact 25 of the central co-axial connector will beapparent. As shown, each of the output co-axial connectors 14 and 16 are provided with resilient reed contacts 36 and 37 arranged to be actuated by suitable push rods 38 and 39 operating in metallic sleeves similar to the sleeves 22and 30. Suitable radial passages through which these reeds centrally pass are also shown in Figure 4 whereby a proper impedance matchY is maintained between any one of the output co-axial connectors and the center co-axial connector.

FromV the above description it will be evident that all of the output co-axial connectors may simultaneously he connected to the center conductor contact 25 of the central input co-axial connector, or any one output in-Y nectors may be immediately placed in electrical c03- nection with the central co-axial input connector without having to switch through the other sections. Because of the relatively small movement necessary to elect a connection or a disconnect, this extremely rapid operation renders the co-axial switch of this invention suitable for a lobing switch on an antenna system. Thus, R.-F. energy may be transferred, for example, between the output co-axial connectors 15 and 17 extremely rapidly by simply alternating energizing pulses between the coils 1S and 25. By the construction of the case 10 and plate 12 the entire operating mechanism may be suitably sealed whereby dirt and dust is kept out of the moving cornponents. Finally, it will be noted from this construction that all of the various connectors face forward and are,

therefore, readily accessible forAmaking necessary co-V What is claimed is:

1. A miniature co-axial switch comprising, in combination: a case having a front electrically'conducting connector plate; a central co-axial connector passing into said plate; at least one co-axial connector passing into said plate and radially spaced with respect to said central connector, said plate including an internal radial passage passing from said central co-axial connector to said radially spaced co-axial connector; a flexible conducting L-shaped reed contact connected to the inner conductor of said radially spaced co-axial connector and passing through said passage and having its free end normally oriented in a first position adjacent to and spaced .behind the inner conductor of said central coaxial connector; and actuating means for pushing the free end of said reed contact into a second position centrally disposed in said radial passage and in electrical engagement with said last mentioned inner conductor with said free end ulcrumed about the junction of the legs of said L-shaped reed contact, said reed contact and passage being dimensioned in accordance with the dimensions of said central co-axial connector and said radially spaced co-axial connector whereby an impedance match is provided therebetween when said reed contact is in engagement with said last mentioned inner conductor of said central `co-axial connector; additional radially spaced co-axial connectors symmetrically positioned on said front plate with respect to said central co-axial connector; additional radial passages in said front plate respectively connecting said additional radially spaced co-axial connectors to said central co-axial connectors; additional reed contacts respectively connected to the inner conductors of said additional radially spaced co-axial connectors, and passing through said additional radial passages to terminate adjacent said last mentioned inner conductor; and additional actuating means for respectively urging said additional reed contacts into engagement with said last mentioned inner conductor individually or collectively.

2. A switch according to claim 1 in which said case is hermetically sealed to said front conductor plate and completely encloses said actuating means whereby a dirt and dust-tight switch is provided.

3. A coaxial switch comprising, a front plate; a p1urality of coaxial connectors all on one side of said front plate and each having an inner conductor passing through said front plate; one of said connectors being centrally disposed with respect to the other connectors which are radially and circumferentially disposed with respect to said one connector; said plate including a plurality of internal coaxial passages, one for each of said other connectors, passing from said one connector to a corresponding one of said other connectors; a plurality of resilient conducting reed contacts, each having one end ailixed to the inner conductor of a corresponding one of said other connectors; each one of said reed contacts extending radially inwardly through a corresponding one of said passages and each having its free end normally spaced behind and out of contact with the inner conductor of said one connector due to the inherent resiliency of said reed contacts; a plurality of actuating means, one for each of said reed contacts, for moving the free ends of corresponding reed contacts into engagement with the inner conductor of said one connector, each actuating means comprising an electromagnet coil coaxially disposed with respect to a corresponding one of said other connectors; and a plurality of push rods, one operated by a corresponding coil, and having their axes circumferentially disposed with respect to each other about the axis of said inner conductor of said one connector, for moving a corresponding reed contact into engagement with the last mentioned inner conductor, said rods being all normally urged out of operating position by said `resilient reed contacts, each of said rods being slidably mounted in a metallic guide bushing which is electrically connected to said front plate, and each of said resilient reed contacts normally urges itself into engagement with a corresponding one of said sleeves, each of said resilient reed contacts comprising tw`o legs of an L-shaped reed contact with the free end thereof fulcrume-d about the junction of said legs, said actuating means moving said reed contacts either singly or collectively into engagement with said inner conductor of said one connector.

References Cited in the le of this patent UNITED STATES PATENTS 2,432,230 Dorne Dec. 9, 1947 2,472,274 Beleskas June 7, 1949 2,498,907 Atwood Feb. 28, 1950 2,584,901 Miller et al. Feb. 5, 1952 

